Aurora trout (Salvelinus fontinalis timagamiensis) / : COSEWIC Assessment and Status Report on the Aurora Trout (Salvelinus fontinalis timagamiensis) in Canada

Aurora Trout are distinguished from other Brook Trout mainly in terms of skin colouration: (1) adult Aurora Trout lack the yellow spots and vermiculations that typically occur on the dorsal surface of other Brook Trout; and (2) the numerous red spots surrounded by blue halos characteristically found on the sides of Brook Trout are greatly reduced in number or are absent on Aurora Trout. [...] The biomass of Aurora Trout in Whirligig Lake quickly increased after stocking to levels comparable to that of Brook Trout populations in unacidified lakes and growth rates of the fish are similar to pre- acidification. [...] Extirpation of the Aurora Trout during the 1960's coincided with acidification of the lakes to about pH 5.0, the threshold for Brook Trout survival. [...] We speculate that the failure of stocked Aurora Trout to reproduce in most non-native lakes is due to the lack of suitable groundwater sites for spawning in the new lakes. [...] Special Significance The Aurora Trout is a unique subspecies of the Brook Trout that is native to only two lakes in the entire world.